ICAO aircraft emissions metrics claimed ‘not fit for purpose’

ICAO’s environment committee CAEP has agreed a metric system that will be used to define a global CO2 standard for new commercial aircraft. Agreement on a common metric for measuring the CO2 emissions of new aircraft has been welcomed by the aircraft manufacturers as well as airline associations and non-governmental organisations. However, the metric has attracted criticism from certain quarters. It has been accused of being politically expedient and lacking in transparency.

Dimitri Simos of UK company Lissys, which created the Piano aircraft analysis software that is used to quantify CO2 emissions in two out of the four greenhouse gas aviation models approved by ICAO.

In a nine-page open letter disseminated before the CAEP agreement, Simos described the metric as fundamentally flawed, unfit for purpose and a deeply wrong decision. “The makeshift proposal devised by ICAO is an unsafe public placebo that utterly fails in its purported intent. Different aircraft emit CO2 differently in transporting specific payloads over specific ranges. ICAO’s CO2 metric is unable to reflect this fact – it measures nothing real and can offer nothing real.”